The present invention is related to identifying a Gram-positive organism that degrades fats, oils and grease. More particularly, the present invention is related to providing a non-pathogenic, spore-forming Gram-positive, lipophilic bacterial strain that produces extracellular lipase and also efficiently oxidizes or degrades fatty acids and grease. The invention is further related to a liquid and dry formulations comprising said Gram-positive organism and a method for enhancing fatty acid degradation employing glycerol.
Most food service establishments are required to have a device that prevents grease from flowing directly from the kitchen or food preparation area into the sewer or to an on-site waste disposal system. Commonly called grease traps, these devices function to physically prevent oils and grease from flowing directly into the sanitary sewer and to store the separated grease solid for eventual solid waste disposal.
Many municipalities place restrictions and surcharges based on the biological oxygen demand (BOD) and oil and grease (OandG) levels in the effluents from grease traps. In addition to wastewater treatment costs and surcharges, the grease solids from the traps must also be periodically removed and disposed. The food service establishment then faces two recurring charges for wastewater treatment, one a municipal treatment cost and secondly a grease disposal cost.
However, the frequency of pumping the accumulated grease solids can be quite variable, ranging from several weeks to several months. If traps are not cleaned on a regular basis, grease clogs may occur causing wastewater to back up into the food preparation area causing malodors and requiring the establishment to close until the problem is corrected. In addition to providing physical means to trap OandG, grease traps can function to biologically mediate a reduction of BOD and OandG in the bulk liquid resulting in cleaner effluent wastewater. This reduction of BOD and OandG is dependent upon the hydraulic retention time, which is dependent on the size of the grease trap and wastewater flow. Other factors that affect biological activity within a grease trap include pH, temperature and whether or not the facility practices bioaugmentation.
Bioaugmentation, the addition of commercial bacterial products that increase the biological activity in the system, has been used to reduce the BOD and OandG in the effluents from grease traps. This has helped to reduce surcharges that the food establishments must pay to municipalities for wastewater services. Additionally, bioaugmentation has been used to decrease the pumping frequency of grease traps, to keep drain lines open and to reduce malodors.
In addition to grease traps, bioaugmentation has also been used to help remove grease from lift stations, drain lines, septic tanks, waste treatment facilities and other situations where grease accumulation can cause flow problems and malodors.
Bioaugmentation products can be either liquid or dry. Because of ease of handling, liquid products are generally preferred and can be added by a liquid metering pump drawing on a container that is replenished on a periodic basis. However, dry formulations are preferred for other applications such as waste treatment facilities.
Strains used in bioaugmentation of grease applications produce an important extracellular enzyme, lipase. This enzyme hydrolyzes and breaks the ester bond between the glycerol backbone and the fatty acid moieties making up the grease. The glycerol is quickly disposed by biodegradation. However, the fatty acids are difficult to degrade and can persist causing pH drops, clogging and malodors.
When Gram-negative microorganisms are used for bioaugmentation in liquid products, they are present as vegetative cells and as such, they may be killed by chemicals, such as surfactants and preservatives, which are often used in such formulations. Therefore, products containing Gram-negative organisms cannot contain biocides and surfactants. Then, unpreserved liquid products may develop severe malodors from microbial contaminants growing in the product. Some of these contaminants may be undesirable in a food service environment. Furthermore, unpreserved products may also suffer from decreased shelf life and efficacy. Clearly, while Gram-negative microorganisms have an advantage in fatty acid degradation, their use in residential and food service products have serious drawbacks.
Dry Gram-negative products, on the other hand, do have an advantage of improved shelf life over liquid Gram-negative formulations. However, this advantage is modest and varies significantly from bacterial strain to bacterial strain in the product. Although dry products can be rehydrated with water and applied like liquid products, the disadvantages of using unpreserved liquids containing Gram-negative microorganisms still apply to rehydrated dry materials.
Many Gram-negative microorganisms are known to have the ability to biodegrade fatty acids generated by the action of lipase. This ability to oxidize and degrade fatty acids is generally not found in Gram-positive spore-forming microorganisms, specifically members of the genus Bacillus. 
Accordingly, there is a need to develop bioaugmentation formulations that can effectively and efficiently degrade or oxidize fats, oil and grease without causing malodors or other undesirable conditions, such as occurs with Gram-negative organisms.
Specifically, there is a need to find non-pathogenic, spore-forming Gram-positive, lipophilic bacterial strain that produces extracellular lipase and efficiently oxidizes or breaks down fatty acids and grease. Heretofore, such a Gram-positive organism and a formulation containing the same have not been identified or produced.
If fatty acid degrading microorganisms are identified, there is a further need to augment or enhance the fatty acid degrading activity of such microorganisms in order to maximize the effectiveness of products based thereon.
It is, therefore, an object of the present invention to provide a non-pathogenic, spore-forming Gram-positive, lipophilic bacterial strain that produces extracellular lipase and also efficiently hydrolyzes or degrades fatty acids and grease or a mixture of fatty acid and grease.
It is a further object of the present invention to provide liquid and dry compositions comprising a non-pathogenic, spore-forming Gram-positive, lipophilic bacterial strain that produces extracellular lipase and efficiently hydrolyzes or degrades fats, oils and grease.
An additional object of the present invention is to provide a method for degrading fatty acid and grease using a Gram-positive strain of Bacillus species.
Yet another object of the present invention is to enhance the biodegrading activity of Gram-positive strain of Bacillus species.
A further object of the invention is to provide a method for augmenting fatty acid degrading activity of microorganisms employing glycerol as an activity enhancer.
Various other objects and advantages of the present invention will become evident from a brief description of the drawings and detailed description of the invention.
Additional advantages and novel features of the invention will be set forth in part in the description that follows, and in part will become more apparent to those skilled in the art upon examination of the following or upon learning by practice of the invention.